


Trouble in Paradise

by dontbecooler, SuperOreoManRPs (SuperOreoMan)



Category: Sherlock (TV)
Genre: M/M, Magic, Merlock, Mycroft's Meddling, POV Multiple, Prince Sherlock, Protective Mycroft, im so sorry
Language: English
Status: Completed
Published: 2014-12-07
Updated: 2014-12-07
Packaged: 2018-02-28 10:44:43
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 1
Words: 13,229
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2729495
Author URL: https://archiveofourown.org/users/dontbecooler/pseuds/dontbecooler, https://archiveofourown.org/users/SuperOreoMan/pseuds/SuperOreoManRPs
Summary: <blockquote class="userstuff">
              <p>Sherlock just wanted a day at his own little paradise, that's all he wanted. He didn't want the stupid human drowning on his watch either, or his little paradise would be swarmed with people. </p><p>Sherlock needs to choose, and either one will have consequences, but which outcome will he choose?</p>
            </blockquote>





	Trouble in Paradise

**Author's Note:**

> Yo it's another one of these! Exciting! Special thanks to the lovely SuperOreoMan, she's the bro and I adore her! I also apologize in advance for what we plotted... That's all I'm going to say ;)
> 
> ENJOY XX
> 
> Side note: *PLEEEEASE CHECK TAGS!*  
> –Oreo

Sherlock was floating leisurely on his back. It had taken a lot of planning to get away from his horrid pod and have some time alone. The little secluded beach was his perfect place, no humans ever came there, and Mycroft knew nothing about it. Sherlock rolled onto his stomach, diving down and watching his tail with glee. It was the same color as his ice blue eyes. When Sherlock came up for air, he heard it, a yell, then splashing. He dove under again, feeling a lot of self-preservation. He saw the feet of a young man over by the rocks. He must have slipped in. The splashing was steadily becoming less and less, and Sherlock decided that he probably shouldn't let the human drown. If he died here then more people would come and find out about his beach. He swam quickly over to the rapidly sinking body and pulled it up above the water. Luckily, and foolishly on the boys part, he had come alone. Sherlock pushed the boy onto the rocks and pulled himself next to the body, rolling the suddenly quite attractive but pale blonde onto his side. Frowning, Sherlock didn't know how to continue. He was out of the water, why wasn't he alive? Sherlock slapped the boys back once, and suddenly the bright blue eyes snapped open, and the boy vomited up the clear sea water. As he coughed and spluttered Sherlock sat with his head turned to the side as he waited.

 

John... well, John was an idiot, and had come alone to the beach and then slipped into the water, idiot that he was, without being able to swim. The sea had always fascinated and terrified him at the same time, and he couldn't help himself. Luckily for John, however, there _had_ been someone there, and he'd saved his life. He coughed up the last of the disgustingly salty water and gasped for breath, allowing himself to breathe for a bit before turning to his rescuer. He stared at the man sitting next to him, still trembling and breathing heavily. "Thank you," he said gratefully, his voice hoarse from the seawater.

 

Sherlock frowned slightly. He didn't know what the human was saying, though it sounded like some sort of thank you. The merman hummed in a non-committal kind of way. The Human wasn't dead; therefore his beach was still his sanctuary. "Ní raibh sé i bhfad de fadhb," he rumbled in reply, in his own tongue, tail, bare chest and hair glittering with specks of water that hadn't dried up yet.

 

John studied the man's face, his foreign tongue lost on him. He opened his mouth to speak again, but obviously they wouldn't be able to understand one another. He looked down... and froze. A tail. A tail? He had a... tail. Instead of legs, there was a long, shimmering, blue, scaly tail, still sparkling with droplets of water. John looked back up to his rescuer's face in confusion, finding that his eyes matched the shade almost perfectly.

 

The merman canted a brow at the man’s expression. "Tá rud éigin cearr?" He asked. Of course it was somewhat obvious what he was looking at, but it didn't hurt to converse a little. The man was literally unable to take his eyes of his tail, which he flicked slightly with a smirk.

 

It was beautiful, really; magnificent. John's eyes found their way to the strange tail again, lost in the way the sunlight danced off the glittering scales. "I... you're a..." John began and trailed off, dumbstruck and realizing that the... merman? ...wouldn't be able to understand him anyway. He forced himself to drag his gaze away from the merman's tail, and looked up at his face again. A handsome face, John realized with a flush. "You're one of the merfolk... from the tales..." He found himself saying, lost in those curious, icy eyes.

 

Sherlock blinked slowly. He had no idea what the boy was saying. He decided to let that be spoken. "Tá a fhios agat nach féidir liom a thuiscint ceart?" He smirked lightly. Why was he blushing? Was it the tail? It was probably the tail now that he thought about it. He looked down at his lower body, the bright scales like gems meshing together around a multitude of find that abled a bigger variety of movement. He flicked it slightly, huffing and looking back up. There was one way he would be able to understand but he wasn't going to do that.

 

John just stared at him with wide, blue eyes, completely lost. Even if he _could_ understand him, he didn't think he'd be able to respond in any sort of coherent sentences. John's attention was drawn to a fin fanning out from the mer's side, and he couldn't help himself from reaching out to brush light fingers across it.

 

Sherlock flinched, letting out an animalistic hiss. "Cad tá ar siúl agat?!" He growled, slapping the humans hand away. No, that was not okay. Would the human allow him to stroke his leg? No. He wouldn't. So why was it appropriate for him to touch Sherlock? "Níl a fhios agam a cheapann tú go bhfuil tú ... ach ní mór duit a stopadh," he drawled, narrowing his eyes slightly.

 

John shrunk away—as though expecting something worse than just having his hand batted away and a growl of warning—withdrawing his hand immediately. "I'm sorry!" he apologized earnestly, his voice jumping an octave. "I-I just... You're fins are... so pretty... Um... and you can't understand me at all, but... you're... very beautiful..." John flushed at his own idiotic-sounding words, suddenly very _glad_ for the language barrier. He fidgeted with his hands for a moment, wondering if he should leave, if he'd overstepped boundaries. Well, obviously he had, but now he wasn't sure what the best course of action would be.

 

Sherlock scoffed and rolled his eyes at the human's slightly abused expression. He would let him be, then, but that would be his only chance. And now he was blushing again. He let out a slow sigh, deciding to get some sort of conversation going. He pointed to his bare chest, speaking very slowly, "Is é mo ainm Sherl'ck." He said; name clicking pleasantly in his own tongue. He then pointed to the human. "Cad é mise?" If the blond didn't understand this he must be extremely thick, and was not worth his time.

"Sherlock?" John asked uncertainly. He must mean that's his name. Then the merman—still such an odd word to think—pointed at John and spoke questioningly. He wanted to know his name. "John," he replied, placing a hand on his chest. "My name is John."

 

Sherlock smiled now. So he wasn't thick. He ran the name over in his mind, John. John. He hadn't heard anything like it before. It was very unusual. And to hear his own name spoken, well, that was weird also. The human didn't put the right inflections on the letters, but that was fine. Sherlock doubted that he'd be able to say John correctly either. He held out a hand, having seen humans do it before as greeting. "Dia duit Jawn," he said, keeping the smile in place. His mouth didn't say the name like the other human had said it; it didn't fit really around his tongue. Oh well, to each his own. When the blond hesitated, Sherlock looked pointedly at his hand. "Dia duit," he said again.

 

John gave a small grin at the way Sherlock said his name. He spoke it a bit... differently, but it got the point across. Tentatively reaching out his own hand, he attempted to relay the greeting while shaking his hand. "Dia... gwit?" John tried slowly, uncertainly.

 

Sherlock managed about two seconds before having to bring his hands back to stifle laughter. He appreciated the effort, of course he did, but it was still amusing. He spoke quickly for the first two sentences, knowing that John wouldn't be able to understand. "Go raibh thar cionn. Dáiríre, tá tú riamh chuala Ghaeilge? Aon, go raibh maith agat áfach, go raibh áit gleoite." He slowly down then, pointing to John. "Conas a dhéanann tú a rá dia dhuit i do theanga?" He moved his hand like a speaking mouth, pointing to John and tilting his head like a curious cat.

 

John mustn't have said it correctly. He ducked his head sheepishly as Sherlock began to laugh, presumably _at_ him, and then rattled away in his own tongue. John stared at him a moment longer, admiring the lilt of the words even if he didn't know their meaning. "You know I have no idea what you're saying, right?" he wondered aloud. He shook his head with a little smile, watching Sherlock as he mimed talking. "Um... in my language?" John guessed, recognizing the greeting from earlier amongst the strange words. He took the mer's hand to shake it again in a more familiar greeting. "Hello. I'm John."

 

Sherlock frowned in concentration. 'Hello, I'm Sherlock,' he thought to himself. What weird words. How could anyone speak like that on a daily basis? "Haloo, eym Sherl'ck," he said, wincing as it came out completely wrong, but he shook once, tail flicking in irritation.

 

"Not too bad," John assured him, patting Sherlock's hand reassuringly with an amused smile that lit his eyes. He shrugged. "Got the point across, anyway."

 

The merman shrugged slightly. He didn't know what the other was saying. So he sat, watching the human, unsure how to continue. He could just dive off the rocks now and swim back to the pod, but he liked this boy. "Raibh mé in ann a rá na rudaí is randamach agus ní bheadh na léitheoirí a fhios fiú," he said, looking John's body up and down. Weird legs, how could you only live on land? Must be an interesting life though, being able to stand up and breath forever in the air. Sherlock could already feel his scales drying slightly; he'd need to jump into the water soon.

 

John studied Sherlock with a frown. "Now, you _know_ I can't understand you, so I don't know why you keep going off on tangents," he said almost frustrated, though he was speaking mostly to himself. He watched Sherlock as he examined John's legs with interest. He was probably as fascinated by them as John was by his tail.

 

This was annoying, not knowing what John was saying. There was a way he could... But, that would scare him off. Maybe he could try to explain. "Dom," he said, pointing to himself, "tú a thuiscint," then pointing at John, "má táimid póg." He kissed his hand and pointed at himself then to John. He pursed his lips, hoping the human would understand him.

 

John blinked in confusion, his eyes following Sherlock's movements with half-understanding. He... did he want to kiss his hand? Was that a mermaid thing? He cocked his head but offered his hand forward a bit.

 

Sherlock shook his head angrily, letting out a small curse in Gaelic. He scooted a little bit closer to the human, touching his own lips with a finger and then John's lips. He raised his eyebrows. "Haloo," he said slowly, "Dia dhuit, haloo." His tongue darted out to touch his bottom lip.

 

"A... kiss..?" John asked, a bit startled at Sherlock's outburst and frustration. He wanted to... kiss John? At least, that's what John was taking from his motions. And he said 'hello' in both their languages while doing it. So... This was how merfolk said hello? John flushed a little at the thought as he realized he didn't think he'd mind kissing Sherlock. He gave a little nod, blushing a bit darker. It was just to say hello, right? And Sherlock _had_ saved his life, after all...

 

The merman scooted even closer, touching John's cheek lightly and pressing a soft kiss to the warm lips. He had assumed he'd have a cooler body temperature, living in the water all the time. He pulled back, feeling his mind swirling with basic magic; he looked into the sapphire eyes as his brain clicked together. It would take a few moments, but soon he'd be able to converse. He sat back completely, closing his eyes and then opening them. They shone with white light for only a moment, he blinked once and it was gone. "Needed to dew it for understanding," he said carefully, watching the human.

 

John was a bit dazed for a moment. "What?" he asked, distracted. "You needed to—wait, _what_?!" He snapped out of his trance as he realized that... Sherlock was speaking _English_? John narrowed his eyes and opened his mouth to call the mer out on knowing what he'd been saying all along when he realized what Sherlock had actually said. "You...  needed what?"

 

Sherlock frowned. "For understanding. A kiss from the speaker." He offered a small smile. He had seemed to make John slightly flustered. "Though, kiss was nice too." He chuckled. "You seem," he thought for the word, "confused. You no understand hmm?"

 

"Oh..." John replied as though he understood. And then flushed again when Sherlock said the kiss had been nice. John pulled his knees up against his chest and wrapped his arms around them. He shrugged—he _was_ confused. "You... needed a kiss to speak English?"

 

The merman nodded. "Mermaids hold basic magic, this be one." He smiled, tilting his head at what John did. Thinking of how he can't do that, Sherlock felt his tail drying out. He frowned, flicking it slightly. The fins twitched, but the scales didn't glitter like jewels. He made a displeased noise. That was not good. He'd been above water for far too long. "Tail drying," he informed, looking back to the human.

 

John looked back to Sherlock's tail, which didn't glitter quite like he thought it should. He then looked out to the water, his lips pouting into a disappointed frown. "Do you have to leave?" he asked a bit sadly, his eyes finding the mer's again. They had only just started speaking to one another...

 

Sherlock hesitated. "Well..." He said slowly, trying to think of a way that they could keep conversing. This was extremely unusual and interesting. "You come into the water accompanying me," he offered, swishing his tail side to side absently.

 

***

Mycroft was sitting out in the bay, eyes narrowed. He'd sensed Sherlock using magic, and had followed him. His little brother was talking with a human, he'd learnt the language. The human knew. And he couldn't be allowed to share. The older prince went under the water, so he didn't get seen. Something would have to be done about this situation.

***

 

John's gaze darted to the water and he shifted anxiously. "I don't know," he replied quickly, unconsciously leaning away from the waves. He wasn't overly fond of the water, seeing as he couldn't swim, although his fear contradicted the curiosity he felt when he thought of the sea. "I... can't swim very well. Or at all, really," he admitted sheepishly, although Sherlock must already know that.

 

Sherlock snorted lightly. "I've seen." He stated, rubbing Johns hand lightly before pulling back and shuffling closer to the edge. "But I happen to be excellent swimmer," he gestured hugely to his tail, moving all the fins at one time to show off. "I'll help you." He looked to the human, thinking that his fear of the water was irrational. The water was a life giver. It was the reason the world revolved. John was slightly slow, he had realized, so the merman had taken it upon himself to aid the blond.

 

John still hesitated. He trusted Sherlock, obviously, but still... He looked back at the merman with wide, uncertain eyes, worrying his lip nervously. After looking between Sherlock and the ocean a few times, he finally nodded his head slowly, trying to seem braver than he felt.

 

Sherlock grinned, not hesitating to slide into the water. He landed on his side not-so-gracefully, but recovered and surfaced, spurting a fountain of water out of his mouth. He called up to John, the fall wasn't that much. "Come, Jawn, come!" He said, opening his arms to catch him. He didn't think John would be half as graceful as him, and he smirked.

 

***

Mycroft heard his brother hit the water, it was easily recognizable. He went right to the bottom on the bay, speeding along the bottom of the water to situate himself by the base of the rocks, waiting patiently for the time to chide his little brother for being an idiot. Was he mad? Sharing his secret with a human? What if it had been a different person, human's couldn't understand them, they never did. They would harm their own kind, not just other species. It was a danger, for even one to know about them.

***

 

John leaned over the side of the rocks to watch Sherlock drop, breaking into nervous laughter at his showing off. He looked over his shoulder for a moment, as though expecting there to be some other John behind him that Sherlock was talking to. His anxious gaze returned to the mer, and John closed his eyes to just go for it. Without allowing himself time to hesitate, John was already halfway to the water, only then starting to panic. He plunged under the waves and sank for a moment before beginning to flail his limbs in a poor attempt to swim, which somehow brought him sputtering back to the surface.

 

Sherlock immediately swam to John's side, trying not to snicker at the boy’s poor attempt at swimming. He scoffed at John still wearing all his clothes, it was obvious they were dragging him down, but didn't say too much about it. The merman wrapped his arms around the flailing boy, holding him up as his tail kept them both above water. "You scared," he stated, feeling the boy’s frantic heartbeat and frowning. "Why?"

 

John clutched at the merman frantically, wrapping his arms around his shoulders and legs around his waist to keep himself afloat. "Because I almost just _drowned_ ," he replied breathlessly, eyes squeezed shut. "And I've just gone back into the water again."

 

Sherlock hummed. "I've drowned before, I am not scared," he stated, though he kept his grip firm on the human. "You need to breath," he rumbled, slowly moving away from the rocky outcrop and further into the bay.

 

"You have not," John argued, daring to pull himself away just enough to look accusingly into Sherlock's eyes. He didn't notice that they were moving further from shore as he stared at the merman. "You can't drown, you're half fish," he grumbled, burying his face in Sherlock's shoulder again.

 

"Fish drown," retorted the brunet, twirling them in a soft circle to survey his hide away. It was so tranquil, so lovely. He would come to this place forever. "If water runs through their gills weird, breathing is impossible." His English was slowly getting better, running off his tongue easier as the words started clicking in mind easily. "I almost drowned last year. I decided to pick a fight with many a bitchy dolphin." He hesitated. "Turns out they don't like being called gay sharks." He snorted lightly.

 

John looked up at Sherlock in surprise, until he abruptly burst into laughter. As he laughed, the tension in his muscles came undone, and he relaxed into the merman's arms. John's legs were still wrapped snugly around Sherlock's hips, the feeling of his muscles undulating beneath him as he kept them afloat somehow comforting. John's laughter died into soft fits of giggling, and he stared up at Sherlock, eyes sparkling with amusement. "You were bullying dolphins?" he asked, barely suppressed laughter making his voice waver.

 

Sherlock tilted his head slightly. "It's not as bad as you think," he said carefully, smiling at the human smiling. "They were stealing our seaweed crop. Little shits." He grinned, pleased that John was starting to relax in his arms. "So rude, they think they're the kings of the sea," he scoffed, "but have you _seen_ me?"

 

John couldn't help but let out another breezy laugh again at Sherlock's description of the dolphins. He'd love to watch _that_ interaction... "Are you implying that you think _you're_ king of the ocean?" John asked with a grin, quirking an eyebrow.

 

Sherlock raised his eyebrows. Of course John didn't know about his rank. "Not king, but I may be in line for the throne." He grinned, blinking slowly as he revealed himself. "Prince Sherlock?" He offered, a slight color touching his cheeks.

 

John raised his eyebrows. "Really?" he asked, almost not believing it. "You're a... prince?" And here he was, helping John—the idiot human that couldn't swim—keep afloat. He flushed a bit himself, and a wave of gratitude swept through him. "Well... thank you for saving me, Prince Sherlock," he said softly with a little smile, leaning forward a tad to press a chaste kiss to the merman's cheek in thanks. He pulled away, blushing furiously as he hesitated to meet Sherlock's gaze.

 

The merman blinked slowly. He looked confused, but his eyes flashed suddenly, and he pressed a soft kiss to John's nose in a gesture so completely and utterly confusing and he didn't know why he did it, but it felt so right and he smiled hugely and swallowed. "You're welcome Jawn," he breathed, cheeks going a pretty pink that contrasted with his eyes.

 

John started in surprise, but melted into a pleased grin when Sherlock spoke. He cuddled into Sherlock's neck contentedly, twirling a finger around a stray lock of hair. John finally, tentatively, let his legs drop from around Sherlock's waist now that he was a bit more comfortable, kicking them experimentally in the water.

 

Sherlock hummed pleasantly at the warmth against his neck and then chuckled at Johns movements. To a normal person, they seemed fine, but to Sherlock, well, they were jerky and untamed. He stifled it though, managing to cough it out as he hugged John too him. He wasn't so bad, this human, and he seemed to like him. Not many people, mermaids, dolphins, humans the lot, they didn't seem to catch on. Yet John did, and that made Sherlock happy.

 

John could feel Sherlock's repressed laughter against his chest, but tried to ignore it, suddenly self conscious of his swimming abilities. He tried to even his lurching strokes, tried to make them smoother and more leisurely, which was difficult because then he'd dip a bit and instinctively start kicking more frantically again. John was doing the best he could, after all, and he didn't even know how to swim, so of course his movements would seem ungraceful to a mer! "Oh, shut up..." John grumbled as a retort to Sherlock's unspoken tease, hiding his hot embarrassment against the merman's chest.

 

Sherlock made a little grumbling noise in his chest. He pulled John back slightly, the merman tilting his head and frowning as he watched John trying to move. He narrowed his eyes slightly at John's technique, and let out a small breath. He remembered how John had surfaced, clumsy and completely unaware of what movements he had to use. "Do you even know how to swim Jawn?" He asked, his tone calm and non-accusing, as it seemed the human was embarrassed by his inability.

 

"No," John finally admitted, ducking his head even though Sherlock was remaining soft and understanding. "No I don't. I never learned," he spoke up a bit louder.

 

The merman frowned, pulling John back to him but not letting him hide himself by pressing into his chest. "So you do not know how to swim, yet you came to the ocean and walked around the rocks?" His tone was actually curious, not condescending in any way as he felt the human shiver slightly. This was not usual, and Sherlock was trying to figure out answers.

 

"I... like the ocean," John admitted, looking back to where they'd come from. His grip around Sherlock tightened when he realized how far away they'd drifted, but he tried to relax. Sherlock wouldn't let him get hurt. John turned back to Sherlock with a grimace. "I know it was dumb, but... The water's so interesting," he continued. "The sea is so different from land. After all, there are fascinating creatures like you in here," he added with a bright smile.

 

Sherlock resisted the urge to roll his eyes, shifting John onto his hip more, so he could use one hand for more stability. "You didn't know we existed until quarter an hour ago," he chuckled, hoping John wasn't getting too cold. He sent a small heating charm over to the human’s clothes. Those were the things dragging him anyway, they should be of some use. He looked over to how John was using his hand, and let out an inaudible breath. "Copy what I'm doing," he said quietly, keeping the soft circles he was making with his palm steady.

 

"You aren't the _only_ interesting thing in here—it's a big ocean," John teased, even while doing as Sherlock said. He felt a soft warmth spread across him, making him relax a bit more. As he sifted his hand through the water, he automatically wanted to pick up the pace, but John trusted Sherlock's instincts better than his own frantic ones, and kept his motions as smooth a he could.

 

Sherlock couldn't exactly tell John what to do with his legs, but he thought for a moment. "Now, move your legs as if they were... Uhm... What's the words- eggbeaters. Spinning around in different directions in circles." He did a little mine of it with his free hand, watching Johns legs now to see what he would do.

 

John stared at Sherlock incredulously. What the hell... Egg beaters? He gave it a shot, moving his legs through the water in a hybrid of the way Sherlock had explained and his instincts trying to keep him afloat. He ended up kneeing Sherlock's bulky tail a few times, apologizing profusely afterwards. He thought maybe it was working...

 

Sherlock let out a little growl at John. "You're not listening," he said, trying not to sound angry, as the human was doing the best he could and kept apologizing for mucking up. Sherlock sat silently as he thought of how to describe the eggbeater, because his fingers weren't good models and his tail was worse. After a moment he had found the right words. "The eggbeater is where the left foot moves clockwise while the right leg moves counterclockwise." He raised his eyebrows, hoping John got it now.

 

John looked down at his submerged legs, distorted by the waves. He paused before he started moving them in a faltering rhythm. "Like... this?" he asked carefully, glancing up at Sherlock for confirmation. It was a strange motion, but he felt himself relying less on Sherlock's body to keep him afloat as he continued to kick, propelling himself upward just enough to stay above the water.

 

Sherlock watched, smiling slightly. "Yes," he said softly, leaning back and the smile quickly grew into a grin. "Exactly like that." He watched John’s hand, and touched it, reminding him to use it too. "Soon you'll be able to keep up without me." He released John only slightly, just loosening his grip a fraction, watching the blond.

 

John panicked for a moment, kicking and splashing about wildly until he was able to collect himself and calm his movements. A focused expression took his face, and his mouth pursed into a determined line as he struggled to repeat the motions Sherlock had explained to him. He felt himself lift, bobbing just above the waves, with only limited assistance from Sherlock.

 

The merman saw a look go over the human's face, and smiled as the blond started staying up. "You can't panic in the water," he hummed, tail movements slightly more emphasized. He was getting excited, watching John learn. "Use both hands now, I've still got you." He smiled, though his gaze was touched with concern.

 

John was focused on his arms and legs, watching them work beneath the waves. He grinned triumphantly when he kept afloat. His movements were still jerky and uncertain, but he wasn't dying, at least. It was a small victory, really, just being able to tread water, but to John it felt monumental.

 

Sherlock grinned in reply, actually highly pleased with John’s success. "Now... Do you think you'd be able to put your head under water?" The merman raised a careful brow, lowering himself into the water more with movements of some fins on his tail, so instead of his torso above the water, he was now under to his shoulders, still holding John up slightly but now the tips of his curls getting dipped. "Under the water is beautiful, floating underneath without a care." Sherlock smiled lightly now, tempted to put his whole head under water, but he didn't want to leave John all on his own.

 

"Under... water...?" John repeated slowly, glancing downward dubiously. How far from shore were they, anyway? How far was it to the bottom? He looked up to Sherlock, abashed. "I... I don't know..." he said quickly, averting his eyes. But... Sherlock would make sure he was okay. He wouldn't let anything happen to John, right?

 

Sherlock felt John tense up, he heard the human’s heart rate pick up, and he frowned. "Would you like to go by the rocks?" He asked quietly, pushing up so he was once again level with him. "You could then hold onto the rocks." He gave a reassuring smile, tilting his head and hoping John would make a choice.

 

"Um, sure," John agreed, feeling relieved. He really would love to go underwater, it was just... well, his fear of drowning. But the idea was so tempting, to swim beneath the waves and explore... he blushed, adding a mental _with Sherlock_... because having the mer at his side just made the whole idea much better. John nodded determinedly. "Yes. Okay. I can do it," he answered, as much to confirm his decision as to convince himself that he'd be fine, that he could handle it.

 

Sherlock smiled, and slowly began to move them back to the rocks. "So I was thinking, you'd get your head under, practice blowing bubbles, then, when you're brave enough, we'll get your top off, I'll put it on the rocks, and you can start going under by yourself and I will meet you down there. Bring you back up. How does that sound?" The merman grinned, holding John tightly again as he picked up his tail movement.

 

John nodded, still hesitant, but a bit more confident now. Sherlock would be looking out for him, and would join him. Besides, John could hold his breath for a decent amount of time, so it shouldn't be too bad, really. "I can do that," he agreed, leaning into Sherlock as he towed them back toward the rocks.

 

Sherlock reached the outcrop soon enough, moving John so he could latch onto them instead of the merman, and he dipped under for a second, slicking it back with the salt water and grinning. "See? Not hard. Rather refreshing." He did a little three sixty on the spot, now circling the human and peering at his hands so he was certain the human wouldn't slip off.

 

John had a death grip on the rocks he was using to anchor himself, nervously watching Sherlock swim easily around him. No, he could do this, he'd be fine. He slowly coaxed himself lower into the water, until the gentle waves lapped at his tightly closed mouth. He paused like that, hesitant to go much further.

 

Sherlock let out a hum when he saw John. He was so close. "You can do it Jawn," he murmured, watching the human as the flicked his tail underwater. "I'm right here, you can come right back up if you get scared I promise. There is no need to be frightened, I'm here for you." He grinned, icy eyes flashing and eager.

 

With Sherlock's encouragement, John rose to suck in a deep breath before plunging his head underwater, still clinging to the rocks, and moving quickly before he could change his mind. It wasn't nearly as terrifying as he'd thought it would be, with John in control rather than fighting to swim, and with Sherlock right next to him in case he changed his mind. He didn't move, just stayed where he was, seeing how long he could hold his breath for. When his lungs felt the beginnings of oxygen deprivation, he pulled himself back up again, blinking rapidly as seawater streamed down his face and letting his breath out to be replaced with new air.

"'S'not so bad," he admitted, wiping his eyes and looking at Sherlock with a little grin, wanting to try it again.

 

The merman was grinning ear-to-ear. "Well done Jawn," he said, "it's not bad at all." He swum right up to the human, cheeks pink as he was dove under again. He swum around John’s feet, before resurfacing. "Do it again, practice moving away from the rocks. Practice swimming around, I want to see how brave you are." That comment made him smile lopsidedly. He was almost glowing, he was so pleased with John's progress.

 

Sherlock's complete and utter zeal was rubbing off on John, making him more daring, more excited, more willing to show off. He pushed himself away from the rocks, letting himself tread water for a moment before dunking his head underwater, moving his arms in circles to keep him under. He stayed under for as long as he dared, even getting brave enough to swim out a bit further from the rocks while he was still under.

 

The merman let out an excited squeal, diving under to watch John then clapping his hands when John came up. "Well done!" He said, tail swishing quickly side to side. "Well done!" He repeated, coming forward and pulling John into a hug.

 

John flushed at Sherlock's embrace, ducking his head, pleased with the merman's enthusiasm. "I... might be getting the hang of it," he said with a self-conscious shrug. He pushed Sherlock away a bit, a determined look on his face. "Alright, let me try again," he announced, sucking in a breath and dipping under the waves again.

 

Sherlock smiled fondly. Humans weren't bad at all. This John, John was amazing. Brave and frightened and pink and warm all in one. The merman carefully watched as the human dove, making sure he didn't panic, movements happy and excited.

 

***

Mycroft watched from the depths below, and his deep orange tail flicked in an almost predatory way. Maybe- if the human moved far enough away from his younger brother he could save him... Keep him safe from the wretched man.

***

 

John kept his eyes and mouth tightly closed against the water. He surged downward, pumping his arms and legs to send himself deeper underwater. Sherlock's obvious enthusiasm was positively contagious, and John found himself wanting to show off a bit for the merman. His movements were still jerky, awkward, but he was getting better.

 

Sherlock, after a moment, dove under the water, swimming under and carefully ushering John up to the surface. John was just learning after all, and Sherlock wanted to keep his new friend safe. The water was murky below them, but Sherlock didn't take too much notice. Once they got to air, Sherlock shook his head like a dog, hands just ghosting over John because he seemed to know what he was doing. "You don't want to over exert yourself John," he giggled, skin sparkling in the soft light of the afternoon sun.

 

A burst of bubbles left his nose in surprise at Sherlock's appearance below him. John huffed out the stale air in his lungs and kicked toward the surface again. Once he'd renewed his oxygen, John scoffed and sent a little splash at Sherlock as payback for sprinkling him with water from his hair. "I won't _overexert_ myself!" he denied indignantly. Then he softened with a lopsided grin. "Besides.... You'd be here to save me."

 

Sherlock raised his eyebrows, bringing his long tail around to dunk a huge lot of water on the back of John’s head. "I shouldn't have to save you, that's the point. You need to be good enough to support yourself and not need me." He smirked, eyes twinkling

John sputtered when water was sent spilling over his head, glaring playfully at Sherlock. He sent another mild splash at Sherlock, though if it came to a full-on water fight, John realized he would most definitely lose. "Cut me some slack—I just started this 'swimming' business today!"

 

Sherlock went under briefly, coming back up to make a fountain of the water with a spurt from his mouth. "Exactly," Sherlock repeated, once his mouth was empty. "You need to be treated like a child, because you have the experience of one." He grinned angelically.

 

John stared at him incredulously, feigning offense. "How dare you!" he replied, punctuating his words with a playful splash in Sherlock's direction before ducking underwater to avoid any retaliation. Contrary to what Sherlock said, John wasn't feeling tired yet—in fact, in the water he felt lighter than air, and full of energy—and he kicked away from Sherlock in clumsy strokes.

 

Sherlock scoffed, and hung by the rocks for a few moments, letting John have a head start. The merman looked up to the sky, smirking softly, before pushing off the rocks and propelling himself after the blond, expert movements meaning he caught up in less than thirty seconds, trailing beside the flailing swimmer. He touched John's arms lightly, calling to him through the water with an ethereal song.

 _My John, my Friend, come back up to air_.

Sherlock smiled, twirling under the sea, bright eyes watching to see if his song worked. Their selkie cousins sung often to lure prey, and the trait crossed seas, but merman didn't sing often. Would it work?

 

John's motions stilled, and his skin prickled with goosebumps. There was... singing. Underwater. It was... compelling. Unearthly. Soft and crisp and clear as day, as though the melody was all around him, cradling him with the waves. John let his eyes open, ignoring the sting of the water in favor of seeking out Sherlock. With a few short kicks, he was headed upward again. He didn't realize how badly his lungs were burning for oxygen until he'd finally breached the surface. "Sherlock?" John called out once he'd caught his breath, floundering at the surface as he wiped the seawater from his eyes.

 

The merman watched as John did as he asked, then came up carefully when he heard his name called. "I'm here," he smiled, going closer to John and supporting his lower by wrapping his tail around John's legs. He could see that John may have been getting tired, and decided to lend a hand.

 

John paused, alarmed, when he felt something curling around his legs, but realized quickly that it was just Sherlock. Okay... maybe he _was_ getting a bit tired now... John reached up to put his arms about Sherlock's shoulders, and laid his head against the merman's chest, letting himself relax a little. "What was that?" he asked softly, looking up at Sherlock curiously.

 

Sherlock snaked his arms around Johns torso, balancing his chin on the others head for a small moment before pulling back and tilting his head, mimicking a small puppy. "I was singing..." He murmured, a small frown forming. "Was it not very good?" It was obviously singing, wasn't it? Was it so bad that John couldn't recognize it? The thought that the talent spread through lore wasn't good when Sherlock did it was slightly disheartening.

 

John couldn't help but let out a little laugh at Sherlock's reaction. He thought John didn't like his singing... which was very, very amusing because it couldn't be farther from the truth. " _Obviously_ it was singing," he teased. He shook his head with a small grin. "No it was... it was beautiful, actually. Brilliant, absolutely just... amazing," John admitted without lifting his head to Sherlock's eyes, flushing a bit.

 

Sherlock blinked, tail movements stilling for a mere second before starting up again. He didn't know how to reply, but his chest definitely wasn't tight anymore. "You're getting cold," Sherlock stated instead, sniffing. "You need to get in the sun." He looked up to the rockface- not very tall, but a drop none the less- and cleared his throat. "Can you climb?" He asked, cheeks slightly pink.

 

"I'm not cold," John lied, indignant. Though, when he huddled closer to Sherlock, it did warm him up marginally, and he wouldn't say no to some sunshine right about now. John nodded against Sherlock's chest when asked if he could climb, eyeing the rock skeptically before returning his attentions to Sherlock.

 

The merman smiled. "Go then, get dry and warm up, then we can do some more swimming," he murmured, using one hand to take John's arms from his shoulders. "Go on, I know you can."

 

John sighed as though put out, barely keeping the pout from his face. If it was just about resting and getting warm, he'd much rather do it in Sherlock's arms, but... John knew it would really be best for him to at least dry off for a little while in between, and properly warm up. He grumbled when Sherlock pried John's hands from his shoulders, but gave in. Wiggling to untangle his feet from Sherlock's tail, John pushed off of Sherlock to propel himself forward, kicking his feet to cause as big of a splash back in Sherlock's general direction as he could while he swam.

 

Sherlock snickered, diving under water briefly while John did the thing with his legs. The splash was endearing too, and while the brunet pretended it wasn't, the stifled pout was very obvious. Sherlock scanned the murky water with his bright blue eyes, feeling like someone was watching, but eventually decided he was being paranoid. He resurfaced, shaking his head. "John?" He called, looking around.

 

"Hm?" John replied when Sherlock’s voice broke through his concentration, still focused on making it to the rocks. He'd given up on kicking water in Sherlock's face—it really didn't seem to be getting him anywhere faster—and was now trying to determine the best route to the top. He was going to have a hell of a time climbing back up there, waterlogged as he was.

 

Sherlock focused on the human, and clicked his tongue, diving under and then turning back up, using the power of his tail to propel himself upwards, catching the side of the ledge, and he flung his tail up, rolling onto the surface of the rock face. "Need a hand?" He asked, tilting his head and smiling down at John.

 

John glowered at the ease with which the merman hauled himself on land, and stubbornly refused his offered help. If Sherlock—who didn't even have _legs_ —could get up so easily, then so could John. He finally reached it and tried to pull himself up, but it was difficult to get good footing on the slick rocks. Huffing in exasperation, John finally gave in. "A hand might be... useful," he admitted strenuously as he clung to the edge.

 

 Sherlock grinned when John conceded, bringing his hand down and catching the human by his wrist. With a small grunt of effort and with the pebbles behind him scrabbling together he rolled backwards, dragging John up over the edge. Sherlock must have over calculated, and John came over too quickly, landing squarely on top of the merman. "Why hello," Sherlock greeted, face right next to the blond’s.

 

Halfway up, John's legs caught some footing, and he pushed against the rock to help Sherlock out. This, however, put him smack on top of Sherlock. He flushed, not trusting himself to speak. Their faces were too close—John could feel Sherlock's every breath—and he felt the sudden, strange, overwhelming urge to press a quick kiss to his lips. He warred with the decision for a moment, looking back and forth between the merman's strange, beautiful eyes, their faces a breath away. John went for it. He brushed their lips together gently in a delicate, chaste kiss, then quickly rolled off Sherlock to lie on the ground beside him, pulling his hands behind his head as a makeshift pillow, acting, for all intents and purposes, as though nothing had happened—only the blush creeping up his neck giving him away.

 

It was something Sherlock was not actually surprised about. He'd seen it coming, from the moment John's pupils dilated. And he'd just laid there and taken it. Sherlock ran his tongue over his bottom lip, then rolled slightly on his side, deliberately deciding to be slightly stupid. "Did you learn my language by kissing me too?" He asked excitedly, saying a few quick phrases in Gaelic to make John think that he was trying to communicate.

 

John nodded, his face serious, his eyes all but twinkling. "Oh, yes. Just then you said I'm the nicest human you've ever met, and that it's nice to finally meet someone who doesn't reek of fish." John tried to keep his expression straight, but wound up cracking into a grin at the end as he turned his head to look at Sherlock.

Sherlock grinned too, but cocked a delicate eyebrow. "Are you telling me that you think I reek of fish?" He asked accusingly, the tip of his fins flicking slightly. He took his hygiene very seriously after all, so smelling like fish to the first human he met would not be very good at all.

 

"I don't know," John admitted with a shrug. "It's a bit hard to smell with seawater up your nose." That's how Sherlock had found him, after all. John rolled onto his side, sitting up a bit to lean over to Sherlock. Without giving himself time to back out, he buried his nose in Sherlock's hair, taking a long inhale. "Mm," he laughed as the drying curls tickled at his nose.

 

Sherlock started, not really expecting that, but he laughed, pulling his head away and shaking like a dog. "John, I didn't say what you said I did." He answered, bringing them back to the topic at hand. "So why'd you kiss me?" His small smile was reassuring, but he was entirely curious.

 

John sat up to avoid the spray, giggling a little. Then he flushed when Sherlock spoke. "Well, you don't smell of fish, if you're wondering," he started slowly, delaying his response. He supposed, logically, there was no reason. They'd been close, he'd seen the opportunity, and he'd taken it. John looked down at his feet sheepishly. "I guess just 'cause I wanted to," he admitted, turning red to the tips of his ears and refusing to meet Sherlock's eyes. "Sorry."

 

Sherlock’s eyebrows pulled together slightly, then even more so. "Why'd you want to kiss me?" He asked, putting his hands on the ground in front of him. His tail was feeling slightly uncomfortable, but he wasn't about to leave John when looked rather distressed. "Why are you sorry?" Was he supposed to get this? Maybe the human emotions were not actually explained in the language they spoke.

 

"I dunno." John stared at his feet and shrugged. He sighed. "I wanted to... because… I like you, Sherlock," he confessed, scratching at his neck to hide his blush. God, that was stupid. Why had he done that? He should never have kissed him. Stupid, stupid. "You're nice, and smart, and you saved me and helped me, and..." He swallowed and finally faced Sherlock with an abashed grin. "Sorry, I—I won't do it again."

 

Sherlock tilted his head again, but a smile dusted his lips lightly. It was finally obvious. John was trying to connect with him, trying to do a sort of ritual that would have led to mating if Sherlock was of the same species. "You don't need to apologize for anything. I understand. It's just-" Sherlock cut off, then decided to keep going. "It wouldn't have worked between us, as we are not of the same species, and merpeople migrate a lot. I appreciate it, and kiss me again if you wish... Just, don't get too emotionally attached to me. After today we may never see each other again after all." He put his hand out to touch John's arm. Frankness was key, especially with a young human it seemed.

 

"Oh. Right," John murmured, though his voice was entirely unenthusiastic. "No, no, I know, I just... I thought..." He trailed off, turning his gaze to look out at the ocean, a steady blush coming to his cheeks. Oh, god, he'd made a fool of himself, hadn't he? Of course Sherlock wouldn't want anything to do with him; he was just some idiot human that was too stupid to not fall into the water. _..And kiss me again, if you wish_ , he'd said. The problem was, John _did_ wish. He _wanted_ to kiss Sherlock again. But.... Ugh, he was an idiot. John just scooted over to the edge and let his feet dangle over the side.

 

Sherlock frowned, feeling slightly hurt at the sudden coldness. He had been completely honest, he didn't understand why John was acting the way he was. He managed to scoot next to the human using his strong arms to move his weight around, absently picking off a dried scale once he was settled. Sherlock continued to be confused when John didn't initiate more conversation. He had done something wrong obviously. "I'm sorry, did I say something?" The merman asked, voice innocent, and Sherlock managed to keep all but a small bit of hurt from his voice.

 

John sighed, eyes fixed in his hands in his lap. "No. No, you were right. It's... probably a bad idea. To get... attached." He reached over to pat Sherlock's tail comfortingly, forcing himself to smile again. It was surprisingly smooth, if a bit dry. "Do you need to go back in soon?"

 

Sherlock caught John's hand in his own, and brought it to his lips in a now impulsive show of affection. "I will survive," he reassured, letting the hand fall back into his lap. He swallowed, and felt the need to reassure John that it was not his fault. "I wish we could, be more than mere acquaintances, but we're pod creatures, and you'd need to get a lot better to keep up with us." He offered a teasing smile, squeezing the human’s hand.

 

John decided to go along with the teasing, rather than lingering on the rather depressing turn the conversation was taking. He gestured to his hand, feigning outrage. "So _you_ get to kiss _me_ , hm?" John demanded, eyes narrowed playfully as he huffed in mock indignation.

 

Sherlock scoffed slightly, not letting the humans hand go. "I never said you weren't allowed to kiss me!" He replied indignantly, gaping softly in John's direction. "I was trying to make you feel better!" He didn't miss the fact that John was avoiding the main problem, instead he let him, bringing the hand up again to hold it just before his lips.

 

John eyed Sherlock for a moment without speaking, but didn't move his hand. Then he sighed dramatically. "Well, I suppose I could allow you to keep trying to make me feel better," he acquiesced.

 

Sherlock pressed another soft kiss in place, not really liking how awkward his tail was feeling, but he didn't say anything, kissing further up John's arms then almost pulling him onto his lap, grinning excitedly. "Can I kiss you on the lips?" He breathed, face right near the others. His brown ringlets were falling in his face, but he was too focused on John to mind.

 

John giggled as Sherlock drew his lips further up his arm, twisting a bit when it tickled, but not tugging away, even as he was pulled practically on top of him. He paused when Sherlock spoke, looking up to realize how _close_ he was. "If... you'd like to," John replied softly, light eyes fixed on Sherlock's.

 

Sherlock blinked, then leaned forward, so the tips of their lips were touching by just a hairs breadth. It made Sherlock huff a laugh, and he pulled back, dark eyelashes flitting quickly before he leaned forward again, lingering above the human for another moment before he pressed more tightly, moving one hand to cup John's head.

 

John waited with bated breath, eyes hooded as he waited. After the first time's false start—with a disappointed rush of breath on his part—John was taken a bit by surprise when their lips finally met on the second one. His arms found their way around Sherlock's shoulders, hugging him closer as he tentatively kissed back, not wanting to drive him away.

 

Sherlock hummed happily, and after a moment of hanging suspended, just pressing back enough for it to count, Sherlock pulled away, eyes sparking and cheeks flushing a light pink. The arms around his shoulders were very lovely and warm, and if Sherlock were a cat he'd probably be purring. "You humans are unusual. See, in mermaid culture, there is a lot more biting than kissing pre coitus." He shrugged, and abruptly pressed another kiss in place. When he pulled back, he ran his tongue slowly over his bottom lip. "I may have to introduce this custom to my people, it is a lot more pleasant than biting."

 

John stiffened at Sherlock's words... though he wasn't sure what had bothered him the most; the idea of Sherlock "introducing" this to his people, or the _pre-coitus_ comment. Or maybe it was the thing about _biting_. John could feel his ears burning. "What?" His voice was hardly more than a squeak. He cleared his throat, turning even redder as he did. "We don't—I mean, this isn't—it's not— _Biting_?" he finally scoffed.

 

Sherlock raised an eyebrow and placed a hand on John's cheek, amazed at how bright it had gone. "Yes, nipping and biting around the throat and mouth," he murmured, and leaned forward to catch John's bottom lip softly between his teeth. He let go with a wicked grin, and then it melted into a smirk. "Like that but slightly more forceful."

 

His breath hitched, and he flushed wildly under Sherlock's attentions. "Oh," was all John could say for a moment. It hadn't been nearly as unpleasant as he'd been thinking. In fact, one might even say that he'd— "Well, sometimes....I mean, sometimes all... _that_... is included in kissing," he tried to explain, blushing even brighter a he redirected himself from going down that particular train of thought.

 

Sherlock grinned, and did it again, just to watch John's reaction. He caught the lip with his teeth and almost nibbled at it, and then let go to press a delicate kiss to John's lips. "You like that," he stated, letting the movement of his lips brush against John's. "You like that a lot don't you?"

 

"Uhm..." John started, unable to completely deny it. Also unable to formulate an intelligent response at this point. "Well it was... not bad..." he admitted softly. He shook his head for a moment, as though to clear it. "Th-that's how some humans kiss, too. With... teeth and... stuff." He gestured vaguely to his mouth and neck area. "Around there."

 

Sherlock chuckled again, and moved so he was trailing his lips down John's throat. He bared his teeth, just grazing the tips of them down John's throat, his main artery, the hollow where his neck and his head connected. "You mean here?" He rumbled, and was feeling rather triumphant. He never had tried this with anyone of his kind, and on his first try he was leaving John speechless and stuttering. It was amazing.

 

John shivered. He let his eyelids drop and just nodded his head slowly, biting his lip to keep himself from doing or saying anything embarrassing, and continuing to blush. It wasn't even _fair_ ; the effect Sherlock was having on him. Not fair at all. John cleared his throat. "Yes, that's, um... there." He nodded again, pulling away halfheartedly, if only to clear his head.

 

Sherlock blinked back to himself when John pulled away. It was like he'd been pulled out of a trance. What was he doing? He and John could never have 'this' whatever it was. What was he doing? Sherlock cleared his throat and straightened up, pulling John up too, and Sherlock looked into his into the humans eyes, holding his head still with two hands. "John, I'm sorry. I just- you know I can't let this-" he fell over his words, blinking and shaking his head. "I shouldn't have done that. It wasn't fair. I'm sorry."

 

John's brow furrowed. Were all merpeople like this, or was Sherlock particularly difficult? _Sherlock_ had been seeming to enjoy himself, and John couldn't deny that the experience had been... a good one. He felt his temper flare up—and a part of him realized it was a defensive mechanism as he felt more than a little rejected by the whole ordeal, but that didn't stop it.  He scowled and pushed Sherlock's hands away from him, glaring off to the side and refusing to meet his eyes so they couldn't give away the hurt in them. "No, _I'm_ sorry," he snapped. For what, he didn't know, but... well, it _sounded_ good at the time...

 

Sherlock blinked, and he felt his stomach twist. His tail, he only just realized, was not having a good time at all, and Sherlock hissed a small Gaelic curse. "John, I should have just left once I knew you were safe. My brother’s told me about your kind, they have a tendency to get attached, and I shouldn't have played that angle. I'm sorry, you should just..." He shrugged. "Leave and forget I ever happened." That would be best. Then he could go home and Sherlock would be nothing more than a dream, a story to young ones so they have a belief in the magical. "My brother told me that I shouldn't get involved, and while I'm not sorry for what I've done, it would be best if... We just stop here right?" It was getting difficult to keep himself upright, and Sherlock looked fleetingly at the water with longing in his gaze.

 

John's heart ached. He could see the truth in Sherlock's words, though—maybe he _had_ become attached too quickly, but... Oh, God, it had all been so nice just a moment ago... John looked down and swallowed. "I'm sorry," he repeated softly, sincerely this time. He reluctantly drew his eyes back to Sherlock's, but kept his distance, not wanting to do something wrong. "Well, we could just.... _visit_ , couldn't we? When your... when your pod's passing through?" he asked uncertainly.

 

Sherlock let out a small noise, flicking his tail fin and was pleased when it didn't snap off. "How would we be able to know when that is? How would I be able to keep in contact with you?" He leaned forward and caught John's hands again, staring at them, running a thumb over the small little calluses, managing to keep the expression of pain off his face.

 

John sighed in exasperation, looking up—anywhere but Sherlock's eyes. He shook his head. "I don't know. It was just a thought," he said quietly, his shoulders sagging. His eyes closed. "We could... I don't know, each full moon? Just... come by and check, see if the other's here..."

 

Sherlock blinked, and he pulled back slightly. "John, that's brilliant." His eyebrows pulled together slightly. Why hadn't he thought of that before? "That's the best thing you've said all day!" He pulled the blond towards him, pressing a chaste kiss to his lips. "That means we can keep in contact and watch each other, and if the other doesn't turn up it'll still be a lovely full moon." He grinned, only his tail keeping him grounded to the real situation.

 

John just blinked for a moment. Sherlock... liked his idea. A dumb little smile grew on his face, and he ducked his head and flushed when the merman kissed him. Sherlock _really_ liked his idea. "Er... right. That... it's good, then? Full moons, that's when we can meet?" Plus it lowered the chance of another human happening across them—not that many people came to this area, anyway.

 

Sherlock nodded enthusiastically. "Yes, in the night, I'll swim here, and you'll be on the rocks, and we'll swim and tell stories and kiss and _bite_ it will be glorious!" His smile taking his whole face as hostage. There had never been a Better idea. He'd convinced himself that he and John were nothing more than a fleeting moment, but now that wasn't a possibility. The sun crackled above him, but instead of listening to his instinct he pulled John forward again, kissing him again.

 

John let out an "mph!" of surprise when Sherlock dragged him in for another kiss, relaxing after a moment and leaning into it, a little smile playing at his lips. He made himself pull away after a moment, flushed from praise and excitement and _kissing_. And there would be more of that, as Sherlock had so enthusiastically pointed out, which just made John all the happier. "Would you like to go swimming again _now_?" he hedged, finally picking up on his discomfort. And, honestly, kind of wanting to swim with him again.

 

Sherlock nodded enthusiastically, and moved slightly, only just hearing his scales crack slightly. He'd stayed out of the water a little too long. He swore softly in Gaelic. Surely he'd been out of water exactly the same length of time it'd been when he'd saved John... Maybe John being on his lap had dried the scales more quickly. It _burned_ , it truly did, and Sherlock shuffled slightly, gritting his teeth. This was kind of killing the mood.

 

John took Sherlock's hand and scooted off him, moving to the edge of the outcrop until his feet were dangling over the side. He was practically bouncing—he needed to practice his swimming if he and Sherlock were going to be meeting each month, and swimming together in the dark. "Let's go!"

 

Sherlock chuckled tightly. "You go in first, just hold onto the wall, I'll be in right after you." He smiled, and put his hands on the small of John's back. "Do you want me to push you?" He asked, grinning wickedly but it was pained. Luckily John had his back to Sherlock, so he didn't see the bright blue blood seeping from the cracks in his tail either. Thank any gods for that.

 

John tossed a quick grin over his shoulder, then, without another word, pushed himself off the side. He curled into a ball in the air, landing with a splash that seemed too large for someone of his size, and came bobbing back to the surface after a moment, waiting for Sherlock to come in after him.

 

Sherlock ran a quick hand over his tail, smiling after John and moving so he was closer to the edge. He forced himself over the side, trying to land gracefully and failing miserably. He landed completely on his side, instead of cleanly like he wanted, and he cried out underwater. Oh gods it was painful. He would never do it again.

 

Below, and auburn haired merman looked up sharply from where he was inspecting his nails, eyes narrowing slightly. Was the human hurting his little brother. Mycroft's bright tail flicked, sharp gaze not sharp enough to see right to the surface... He slowly started drifting up, just to inspect the situation.

 

"Sherlock?" John asked worriedly. When the merman didn't come up right away, John looked toward where he'd fallen into the water anxiously. Was he alright? Maybe he'd stayed out of the water for too long, John wondered guiltily. He sucked in a breath to follow him under, leaving the wall and swam closer, reaching out for him, trying to find him even with his eyes shut tight.

 

Sherlock twisted in the water, keening quietly at the burn of the salt in his fresh cuts. He heard John and looked at him, completely the wrong way around, endearingly with his face screwed up under the water. He used his arms to get to John, pulling him back to the surface and back to the rocks. "What are you doing? I told you to wait for me," he rumbled.

 

"I can swim," he complained indignantly once he'd sucked in fresh air, wiping seawater off his face and from his eyes—though he made no move to pull away from the merman's arms. He blinked up at Sherlock, studying his expression carefully. "Are you alright?" he demanded skeptically. "When you jumped into the water, that landing was... well, it was just _horrible_." He cracked a smile.

 

Sherlock narrowed his eyes, trying to use one arm to keep them afloat, because it seemed his tail was having trouble moving and stinging worse than a sea urchin to the nipple. "I am fine," he reassured, and he tried to propel then to the wall with a flick of his tail, but the movement made him cry out. His scales were too dry, and he saw a few of them float to the surface. Sherlock swallowed. He'd never had this happen to him before. "I am fine," he repeated, breaths coming in little pained pants.

 

John's expression hardened. "Clearly," he replied sardonically. He huffed out a breath, but was really far too worried to be too upset with Sherlock at this point. He wiggled free from Sherlock's grip but kept close, surveying the merman. "Let me take a look at you, you great git," he demanded, though his tone was soft. He pulled back. "Now. Where does it hurt?"

 

Sherlock let out a small growl, and didn't like how he couldn't use his tail to keep himself above the water. "General tail area," he drawled, lifting it up to the surface. It was slightly flaky, and there were little streams of blue blood seeping from it. It looked just as bad as it felt, but perhaps it felt worse. At never having felt discomfort this bad in his life, Sherlock did not have a big pain tolerance.

 

John winced sympathetically when Sherlock finally showed him the damage. Had _he_ done that? From sitting on his tail? Granted, it would be Sherlock's fault for pulling him into his lap in the first place, but that didn't stop the surge of guilt from gripping him anyway. "Oh," he started dumbly. He ran a careful hand along the injured area in a way he hoped was comforting. "Sorry," he murmured.

 

Sherlock twisted away and hissed a curse in Gaelic. "Don't _touch_ it," he said, the sentence starting off malicious but quickly turning into a laugh. "It is very painful, and touching it puts the salt further in the cracks. I just need a couple of minutes, then the surface will rehydrate and I'll be able to move properly." They'd learned about this in pod school. It had been dull, very much so, but the little bit of information he'd retained was very helpful actually.

 

John jerked his hand back, looking up at Sherlock sheepishly, guiltily. "Sorry," he muttered again. "Sorry." He bit his lip. "I did that, didn't I?" he asked glumly. "When I was on your lap?" Without waiting for the answer—he knew it with or without Sherlock's confirmation—John looked down again at the mess of cracking and what he could only assume was _blood_ seeping into the water. "Your blood's blue?" he questioned, eyebrows raised.

 

Sherlock raised his eyebrows, and shook his head. "I was out of the water for far too long, I could have hopped in at any point. It's not your fault." He moved his tail just, with another wince. He looked somewhat flatly at the human at the question. "Actually John, that is blue wine. We excrete it. Go, try it, it's delecious."

 

John rolled his eyes and let out a little snort. "Git," he complained fondly, narrowing his eyes at Sherlock before explaining, "No; I mean, our blood—humans' blood—is red. So blue is... a bit odd." He looked down at Sherlock's tail again, watching the streams of strange, blue blood dissipate into the water. "Very odd...."

 

Sherlock barely suppressed a snort. "Would you like to examine it further Doctor Watson," he drawled, lifting his tail up more with a small wince. Already it was feeling better, and soon he'd be back in full shape. His arms were aching, they weren't used to such work when it came to swimming, and Sherlock’s cheeks were pink now due to the effort.

 

"I'll pass, thanks," John replied. Sherlock seemed better, anyway. "Need help swimming?" he offered with a raised brow, taking in the merman's signs of exertion. Without waiting for a response, John swam closer and did what he could to keep them afloat together, treading water for them both. "Seems _you're_ the one who needs help, now," he teased.

 

Sherlock rolled his eyes, using one hand to shove the other under briefly, before bringing him back up to the surface. "Be careful what you say." He growled, chuckling, moving his tail slightly. "Look, you go ahead, ahead as in under, see how far you can go before I can catch you. I’m being boring all injured and such." He grinned playfully, ruffling John's wet here. "I bet it won't be very far at all, but you seem confident."

 

John shot Sherlock a glare as he sputtered to the surface, rolling his eyes and batting his hand away. "Of course I'm confident," he scoffed, swimming away a bit and preparing to dive under. "I _did_ learn from the _best_ , after all," he said cheekily over his shoulder, giving Sherlock a wink before plunging out of sight.

 

Sherlock watched as John disappeared, quickly working on his method of rehydrating his tail. Slow, careful circular movements, to make sure that all was getting the same amount of exposure. Sherlock slow careful breaths, just wanting to catch up to John and tease him. He wouldn't get very far before Sherlock was ready to take chase... Sherlock grinned, tentatively rubbing down his scales.

 

The auburn haired merman was near the surface. Not too far, not too close, but he was close enough to see the human swim away. Sherlock was in pain, he could smell the blood and the tension, and the human was fleeing while Sherlock recovered. Mycroft swam forward silently, running a cautious hand over the humans face. He didn't seem guilty. Mycroft took his wrist, leading him deeper, away from his brother, to the safety of the depths. He would keep his brother safe from this being.

 

John started as a hand touched his face, eyes fluttering open to catch a blurry outline of a merman before the salty water stung his eyes so that he had to squeeze them shut again, relaxing with a frown. Had Sherlock caught up to him already? And here he'd thought he'd been getting a fairly good head start... John pouted for a moment, but let himself be led along. He knew they were getting deeper, and he brushed Sherlock's arm to let him know he was holding his wrist a bit tighter than necessary.

 

Sherlock was almost ready, almost prepared to go, and he ducked his head underwater. He couldn't see John, which was either promising or worrying, Sherlock couldn't tell which. He picked off the last of his scales, wanting to swim to the rocks and back to get his rhythm back before good after the blond.

 

Mycroft only felt a slight bit of remorse as he brought the human even deeper. It was getting colder, even the prince could feel the pressure building, but still he went deeper. He needed to keep Sherlock safe. And this human had hurt his brother. It wouldn't be painful, more like going to sleep. It wouldn't hurt. And Sherlock would be safe.

 

John was fairly certain this was far deeper than he'd ever gone before, and yet still they were going downward. He could feel the weight of the ocean growing heavier around him, pressing against him on all sides and starting to chill him. His oxygen was about used up as well, and John tugged on his arm at the familiar burn of lack of air, trying to pull back toward the surface. They should start heading up now if John wanted to be able to keep holding his breath for the journey back up as well.

 

Sherlock swam quickly, having actually no need to do the warm up, and as soon as he was ready he dove under quickly, calling excitedly. "John!" He sung, searching for a response. "John I am coming!"

 

Mycroft flinched at the tug. He wasn't normally the one to get his hands dirty. He heard his brother, and hissed, picking up the pace. Keep him safe. Obviously Sherlock was under the illusion that the human had cast. Even though he'd been injured he still wanted the humans company. As was the allure of the species. Mycroft’s grip held tight, and he ignored the twisting in his gut.

 

For the first time, John felt a twinge of fear. What was Sherlock doing? He had to know the human wouldn't be able to hold his breath _that_ long underwater, right? John pulled harder this time, jerking his hand back and kicking out with his legs, trying to convey that he needed oxygen and that he needed it _now_. That's right about when he heard it—the song. More specifically, _Sherlock's_ song, Sherlock's _voice_ —and it was _not_ coming from the being next to him. That's when the twinge of fear blossomed into full blown terror. His eyes flew open again, but it was too dark at this depth for him to see much. He pulled away frantically, trying to pry away the fingers of whoever had a hold of him. "Sherlock!" he cried out instinctively. But of course his voice was swallowed up by the sea, the sound lost in a burst of bubbles quickly disappearing to the surface. Now he had even less air, and the depth was beginning to become almost painful.

 

Sherlock heard it, the desperate, frantic shout of his name. Coming from too far down, John wouldn't be able to come back up. Sherlock went full speed downwards, still singing. "Do not fear, my friend, I am coming, just start swimming upwards-" Sherlock cut off when he saw his brother, familiar orange tail so easily visible. " _Mycroft_!" Sherlock shrieked, blood boiling. What was he _doing_? It was too deep, surely he couldn't- " _No_!" he screamed, swimming more quickly even though it reopened the cracks. He collided into his brother’s side; the merman must have been tricking John by going slowly downwards. "Keep holding John, I've almost got you!" He sung, swinging viciously at his kin. "Ligean dó dul ar sé ar mo chara! (Let him go he's my friend!) " He shrieked in Gaelic, grabbing John around his waist with an animalistic desperation he'd never experienced before.

 

Mycroft was flung to the side by Sherlock’s collision, he wasn't even sure how Sherlock had for down there so quickly, but he heard his brother singing and shrieking and was so shocked by his brothers reaction he let go, darting away. He hadn't expected a fight, more only a slight resistance. "Ní mór dó a bás. (He must die)."

 

Sherlock was swimming to the surface as soon as he was sure John was in his arms, breathing erratic. " _NO_!" And he was moving more quickly than he had ever, his tail was burning, but John, John hadn't asked for this. Mycroft would pay, he would die if something happened. "Almost there John, we're almost there," he sung, the light growing as he rose. "Stay with me my friend."

 

The edges of his thoughts were growing fuzzy, but John's heart leapt when he heard Sherlock's voice again. Then he was flung to the side when what was presumably Sherlock came hurtling out of nowhere, knocking them all to the side. Some more yelling—it was getting hard to focus, hard not to just suck in another breath—and then Sherlock's arms were around him, pulling him toward the surface so quickly that the rest of the air in his lungs was lost to the sea in a rush, leaving John terrifyingly breathless. He could still hear Sherlock's singing, so close yet sounding so very far away, his voice comforting even as John's consciousness drifted... His voice was so pretty, John thought, and Sherlock had come to save him, which made him immensely pleased... He didn't know if the tingles in his extremities was from happiness or something else, but all he knew was that he was happy Sherlock had come back for him.... Before... Before it was too late...

 

Sherlocks head broke the surface, and he pulled John up above him. "John, John, breathe, John," he chanted, holding John's head above the water. He kissed him, because kissing him woke the human up, he nipped, he held the other tightly. He slammed himself into the others chest, making him cough and sputter, just like at the start, yet he didn't open his eyes. "John, please, we had a deal, every full moon, every full moon," he was almost sobbing. His friend. His friend. "John-"

 

Mycroft came up from underneath. Sherlock was far too attached. There was no way in Poseidon that he would let it continue. He came up, silent just as death was, and ripped John from Sherlock’s arms, pulling the blond downwards into his own. "Beidh chodladh síoraí a bheith síochánta, (Eternal sleep will be peaceful)," he murmured in the humans ear, grabbing him around the neck and twisting with an animalistic force. The crack resounded, and Mycroft let the corpse drift from his hands.

 

The crack left Sherlock’s ears ringing. He swam downwards, oblivious to his brother, only seeing the body. His friend, his friend, his friend. Sherlock swam around him. "John, awaken, do not play games," he sung, but the words fell upon deaf ears. "I need your help to swim, awaken John." The body only drifted. His eyes were closed, like he were sleeping, but when Sherlock nudged him his neck moved far too freely, like it wasn't truly connected. "John," he tried again, nudging the body before glancing up. He could feel his brother’s pitying gaze from so far below and finally, finally it clicked, that John wasn’t coming back, that the blond he had tried so hard to save dead, gone… Dead. Sherlock’s shriek was so pained and torn as he took off in a direction that wasn't here. There was no paradise, there was no such thing. Full moons and swimming were illusions of the truth. And John was dead.

There were no paradises.


End file.
